81222893 has 2 divisors, whose sum is σ = 81222894. Its totient is φ = 81222892.

The previous prime is 81222877. The next prime is 81222917. The reversal of 81222893 is 39822218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79085449 + 2137444 = 8893^2 + 1462^2 .

It is a cyclic number.

It is not a de Polignac number, because 81222893 - 2⁴ = 81222877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81222803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40611446 + 40611447.

It is an arithmetic number, because the mean of its divisors is an integer number (40611447).

Almost surely, 2^81222893 is an apocalyptic number.

It is an amenable number.

81222893 is a deficient number, since it is larger than the sum of its proper divisors (1).

81222893 is an equidigital number, since it uses as much as digits as its factorization.

81222893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 81222893 is about 9012.3744374055. The cubic root of 81222893 is about 433.0713808649.

The spelling of 81222893 in words is "eighty-one million, two hundred twenty-two thousand, eight hundred ninety-three".